Single-side formwork erecting construction method for well-shaped underground building with special-shaped section

The invention relates to the technical field of retaining walls or protective walls, and discloses a single-side formwork erecting construction method for a well-shaped underground building with a special-shaped section, which is characterized in that a full framing arranged in a barrel formwork of a side wall is used for resisting formwork expanding force, so that the barrel formwork is represented as a barrel which has certain rigidity and can resist inward collapse; then, a single-side formwork supporting frame which is small in size and enough to be placed in the well-shaped underground building with the special-shaped section abuts against the inner side of the bottom of the rigid barrel by a circle, so that the rigid barrel cannot horizontally move under the action of unbalanced formwork expanding force in the horizontal direction, formwork expanding is avoided, and meanwhile it is guaranteed that the thickness of the poured side wall is uniform; and meanwhile, the bottom of the cylindrical die is preve